<?php
/**
 * CFilterChain class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */


/**
 * CFilterChain represents a list of filters being applied to an action.
 *
 * CFilterChain executes the filter list by {@link run()}.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CFilterChain.php 3204 2011-05-05 21:36:32Z alexander.makarow $
 * @package system.web.filters
 * @since 1.0
 */
class CFilterChain extends CList
{
    /**
     * @var CController the controller who executes the action.
     */
    public $controller;
    /**
     * @var CAction the action being filtered by this chain.
     */
    public $action;
    /**
     * @var integer the index of the filter that is to be executed when calling {@link run()}.
     */
    public $filterIndex=0;


    /**
     * Constructor.
     * @param CController $controller the controller who executes the action.
     * @param CAction $action the action being filtered by this chain.
     */
    public function __construct($controller,$action)
    {
        $this->controller=$controller;
        $this->action=$action;
    }

    /**
     * CFilterChain factory method.
     * This method creates a CFilterChain instance.
     * @param CController $controller the controller who executes the action.
     * @param CAction $action the action being filtered by this chain.
     * @param array $filters list of filters to be applied to the action.
     * @return CFilterChain
     */
    public static function create($controller,$action,$filters)
    {
        $chain=new CFilterChain($controller,$action);

        $actionID=$action->getId();
        foreach($filters as $filter)
        {
            if(is_string($filter))  // filterName [+|- action1 action2]
            {
                if(($pos=strpos($filter,'+'))!==false || ($pos=strpos($filter,'-'))!==false)
                {
                    $matched=preg_match("/\b{$actionID}\b/i",substr($filter,$pos+1))>0;
                    if(($filter[$pos]==='+')===$matched)
                    $filter=CInlineFilter::create($controller,trim(substr($filter,0,$pos)));
                }
                else
                $filter=CInlineFilter::create($controller,$filter);
            }
            else if(is_array($filter))  // array('path.to.class [+|- action1, action2]','param1'=>'value1',...)
            {
                if(!isset($filter[0]))
                throw new CException(Yii::t('yii','The first element in a filter configuration must be the filter class.'));
                $filterClass=$filter[0];
                unset($filter[0]);
                if(($pos=strpos($filterClass,'+'))!==false || ($pos=strpos($filterClass,'-'))!==false)
                {
                    $matched=preg_match("/\b{$actionID}\b/i",substr($filterClass,$pos+1))>0;
                    if(($filterClass[$pos]==='+')===$matched)
                    $filterClass=trim(substr($filterClass,0,$pos));
                    else
                    continue;
                }
                $filter['class']=$filterClass;
                $filter=Yii::createComponent($filter);
            }

            if(is_object($filter))
            {
                $filter->init();
                $chain->add($filter);
            }
        }
        return $chain;
    }

    /**
     * Inserts an item at the specified position.
     * This method overrides the parent implementation by adding
     * additional check for the item to be added. In particular,
     * only objects implementing {@link IFilter} can be added to the list.
     * @param integer $index the specified position.
     * @param mixed $item new item
     * @throws CException If the index specified exceeds the bound or the list is read-only, or the item is not an {@link IFilter} instance.
     */
    public function insertAt($index,$item)
    {
        if($item instanceof IFilter)
        parent::insertAt($index,$item);
        else
        throw new CException(Yii::t('yii','CFilterChain can only take objects implementing the IFilter interface.'));
    }

    /**
     * Executes the filter indexed at {@link filterIndex}.
     * After this method is called, {@link filterIndex} will be automatically incremented by one.
     * This method is usually invoked in filters so that the filtering process
     * can continue and the action can be executed.
     */
    public function run()
    {
        if($this->offsetExists($this->filterIndex))
        {
            $filter=$this->itemAt($this->filterIndex++);
            Yii::trace('Running filter '.($filter instanceof CInlineFilter ? get_class($this->controller).'.filter'.$filter->name.'()':get_class($filter).'.filter()'),'system.web.filters.CFilterChain');
            $filter->filter($this);
        }
        else
        $this->controller->runAction($this->action);
    }
}